I also had this question, in addition to possibly disabling it on an certain image class. This does seem to be possible at least for featured images like the original question. They have some documentation here https://make.wordpress.org/core/2020/07/14/lazy-loading-images-in-5-5/ but I can’t figure it out.
Then enabled the lazy load images using a cache plugin/ optimization plugin. In my case, it is LiteSpeed Cache and excluded the featured image class from lazy loading.
Then enabled the lazy load images using a cache plugin/ optimization plugin. In my case, it is LiteSpeed Cache and excluded the featured image class from lazy loading.
That’s actually a good way of doing it. WP’s default lazy load is lacking so it’s better to replace it with a plugin with more control like Litespeed cache or WP Rocket that lets you target an image specifically through its class selector.